Substituent effects on opticalproperties of pyrrolizine-fused BOPYIN

Construction of Boron Difluoride Complexes with Asymmetric N,N'-Bidentate Ligands

Boron difluoride (BF2) complexes with asymmetrical N,N'-bidentate ligands have received increasing attention due to their fascinating properties and broad applications. They are generally constructed in two steps: ligand formation, followed by boron complexation. This review focuses on categorizing these BF2 complexes based on the key synthetic strategies that have been applied in the ligand formation steps. The post-functionalization, properties and applications of different types of BF2 complexes are presented. Their challenges and opportunities are also discussed. This should help the future rational design and synthesis of BF2 complexes with intriguing properties and practical applications.

Study on Photophysical Properties of Novel Fluorescent Phenanthroimidazole-Thiadiazole Hybrid Derivatives

Phenanthroimidazole-thiadiazole hybrid derivatives, which are new heterocyclic compounds with fluorescence properties, were synthesized by designing a two-step reaction mechanism and their photophysical properties were investigated. The synthesized derivatives were purified and their structures were elucidated by ATR-IR, ¹H-NMR, elemental analysis and HR-MS methods. In the next stage of the study, the absorption and emission spectra of the synthesized new phenanthroimidazole-thiadiazole hybrid derivatives were determined by UV-Vis and fluorescence spectroscopy. Stokes' shifts, molar extinction coefficients (ε), singlet energy levels (Es), quantum yield (ϕ_f), lifetimes (τ), the radiative (k_r) and the nonradiative (k_nr) constant for new hybrid derivatives were measured in DMSO. In addition, aggregation measurements, which is an important parameter that changes the photophysical properties were performed and for these compounds, structure: photophysical properties were discussed.

BOPYIN-anil and BOPYIN-boranil complex: Synthesis, spectroscopic properties and ESIPT process

Two BOPYIN dyes (W-1 and W-2) were synthesized, and their structural and photophysical properties were investigated. The absorption bands of both dyes located at ca. 350 and 500 nm in diverse solvents. The absorption profiles are a linear combination of those of the BOPYIN core and the boranil or anil subunits. Their emission spectra were observed at ca. 565 and 540 nm with 14.2% and 77% quantum yield in CHCl3, respectively. The absorption, excitation and emission spectra for both dyes confirm that the boranil or anil moieties could be used as an input energy antenna for cascade energy transfer to the fluorescent BOPYIN residue at 540 nm. Subsequently, ESIPT process of W-1 is fast and more likely to occur in non-polar solvent investigated by DFT calculation.